Method and apparatus for packing christmas tree balls or similar delicate objects



M. SCHMIDT 3,228,167

S FOR PACKING CHRISTMAS TREE Jan. 11, 1966 METHOD AND APPARATU BALLS OR SIMILAR DELICATE OBJECTS 2 Sheets-Sheet 1 Filed NOV. 7, 1962 Jan. 11, 1966 M. SCHMIDT 3,228,157

METHOD AND APPARATUS FOR PACKING CHRISTMAS TREE BALLS OR SIMILAR DELICATE OBJECTS 2 Sheets-Sheet 2 Filed Nov. 7, 1962 United States Patent 3,228,167 METHOD AND APPARATUS FOR PACKING CHRISTMAS TREE BALLS 0R SIMTILAR DELICATE OBJECTS lVIax Schmidt, Brauhausstrasse 17, Ansbach, Germany Filed Nov. 7, 1962, Ser. No. 236,083 Claims priority, application Germany, Nov. 8, 1961, Sch 30,527 5 Claims. (CI. 5329) The present invention relates to a method and apparatus for packing Christmas tree balls or similar delicate objects.

Christmas tree balls and similar delicate. objects are usually packed and sold in cartons in which they are inserted into compartments and are hidden from view by the closed cover of the carton. This manner of packing has the disadvantage that prospective purchasers are unable to see the balls and to consider whether they like their size, shape, and color. Even pictures of the balls which are often glued on the cover of the carton cannot give a purchaser an adquate impression of their actual quality and appearance.

Attempts have been made to overcome this disadvantage by providing the cover of the carton with a window of a transparent material. However, even such a window only permits a small part of the contents of the carton to be seen. Such a carton also has the disadvantage of being rather expensive which, in turn, considerably increases the price of sale of the balls.

The inadequacy of such cartons led to attempts to pack the balls in transparent bags. Since Christmas tree balls at that time primarily consisted of very fragile glass and such transparent bags did not protect them sufiiciently from breakage, these attempts were quickly abandoned.

Different conditions prevail, however, in present times when many of the Christmas-tree balls are made of plastic which, although still delicate, are not easily broken and are capable of withstanding considerable impacts and compression. It is therefore an object of the present invention to provide a suitable package in the form of a transparent bag for Christmas tree balls and similar products, especially of the last-mentioned type. Such a package has the great advantage that its entire contents and thus each individual ball, for example, of an assortment of balls of difierent shapes, colors, or appearance may be fully examined without requiring the package to be opened. This makes the package especially suitable for self-service and similar stores where a customer may select what he wants without having to listen to any sales talk and without having to open different cartons or other containers to inspect their contents.

The transparent bags of the conventional type have, however, the disadvantage that they are relatively unstable and that they together with their contents therefore form more or less loose or flexible objects in which even the relatively unbreakable balls of plastic are not protected from being deformed, for example, by dents or bulges.

It is therefore another object of the invention to provide a transparent bag which overcomes the above-mentioned disadvantages and forms a package in which the balls or other delicate objects may be safely transported without danger of being damaged.

This object is attained according to the invention by making the bags of sheets of transparent plastic, preferably of polypropylene or the like, and by closing these bags hermetically after being filled and after compressing the air contained therein. Thus, a tightly filled air cushion is formed which prevents the balls which are enclosed with the walls of the bag from shifting therein.

3,228,167 Patented Jan. 11, 1966 ice This has the additional advantage that the size of each bag definitely predetermines the number of balls which may be packed therein and that a minimum quantity of sheet plastic will be required for each package.

Although the bags may be filled with compressed air after the balls are inserted therein, for example, by blowing compressed air into the bag and by thereafter welding the air inlet opening closed, this procedure is too complicated in actual practice, especially also since it would require a special blowing apparatus. According to the method of the present invention the compression of the air in the filled bag is principally due to the particular manner in which the bag is sealed, rather than to the injection of any additional air into the bag. This may be done according to the invention, for example, by first .providing the unfilled part of the bag near its open end by means of a pair of welding rods with a hermetically closing welding seam, by then drawing this unfilled part between and through these welding rods while they are tightly lpressing thereon until these rods almost abut against the balls in the bag, and by then using the welding rods to form another hermetically closing welding seam. In this very simple manner the air may be compressed in the bag to whatever rate of compression may be desired and the doubly sealed bag then forms an air cushion which protects the balls from being damaged. By this operation, the balls contained in the bag are also moved tightly against each other so that no unnecessary gaps remain in the bag. This has the advantage that the balls are prevented from moving around in the bag and that a considerable amount of plastic material is saved. The

part of the bag between the two parallel welding seams is then devoid of any air and thus very suitable for printing advertising matter or the like thereon.

The method of compressing the air in the bag may according to the invention also be carried out by means of a pair of welding rollers which are applied upon the oppo-v site sides of the unfilled part of the bag near its open end and are then first used for forming a welding seam along a line near this end. These rollers are then rotated in.

opposite directions while pressing upon the bag so as to draw the unfilled part thereof through them and thereby to compress the air in the filled part of the bag until they are stopped closely adjacent to the balls and are used for forming a second hermetically closing Welding seam. .Of course, instead of forming two separate Welding seams,

for example, by the welding rollers themselves or by two The plastic bag itself is produced in the conventional.

manner in the form of a tubular sheet of plastic which is extended from an extrusion press and is then pressed flatand cut to size and one open end of which is closed at the same time by welding. This bag is then picked up prefer; ably by suction cups or the like and inserted between a pair of conveying chains which run in the same direction, hold the unsealed filling end of the bag in a widely open position, and carry the bag past a series of hoppers containing the balls. By means of a suitable feeding device, one ball is then dropped from each hopper into the moving bag until it is filled with the desired amount of balls, whereupon the bag is conveyed to the welding apparatus in which the open end of the bag is welded shut according to the method of the invention as previously described.

The completed packages are then ejected into a container and stacked therein.

The above-mentioned as well as numerous additional features and advantages of the present invention will become more clearly apparent from the following detailed description thereof which is to be read with reference to the accompanying sheet of drawings, in which:

FIGURE 1 shows a front view of a filled plastic bag according to the invention;

FIGURE 2 shows diagrammatically the extruder and the method steps of producing the plastic bags;

FIGURE 3 shows diagrammatically the mechanism for conveying and filling the bags;

FIGURE 4 shows diagrammatically the method and means for carrying out the first and second welding operations for closing the filled bags;

FIGURE 5 shows a top view of the conveying and filling mechanism; while FIGURE 6 shows diagrammatically a modification of the method of welding the filled bag and of compressing the air therein.

Referring first to FIGURE 2 of the drawings, the extruder 1 which is provided with a blow head 2 ejects a tubular sheet of plastic 3 which thereafter passes through rollers 4 and is thereby flattened. In the subsequent operation, the plastic sheet 3 passes through a welding apparatus 5 and a cutter 6 which operate simultaneously on the flattened tubular sheet to form a plastic bag 7. This bag 7 is then picked up by a suction cup 10 or the like on a two-armed lever 9 which is pivoted by a piston movable in a hydraulic pneumatic cylinder 8 and is then swiveled by another piston in a cylinder 11 to press the bag against a conveying chain 13 which is likewise provided with suction cups 12 and then carries bag 7 in the direction as indicated by the arrow. As shown diagrammatically in FIGURE 5, chain 13 is driven in a step-by-step movement by a piston in a cylinder 14 which also drives by the same intermittent movement another chain 15 which extends substantially parallel to chain 13 and is likewise equipped with suction cups 12.

After being applied upon the suction cups 12 on chain 13, bag 7 also meets the suction cups 12 on chain 15. The two corresponding suction cups 12 on both chains then hold the mouth of the bag widely open, as shown in FIGURE 5, to permit the bag tobe filled. For applying the bag upon the suction cup lz pn. chain 15, a suitable mechanism, not shown, may be used which may be similar to the mechanism 8 to 11. Bag -7 will then be conveyed by the step-by-step movement from one filling station to the other.

The Christmas tree balls 16 are stored separately, for example, according to their different colors, in a plurality of funnel-like hoppers 17 which are mounted above the conveyor chains 13 and 15 and each of which terminates through an opening 18 into a tubular outlet 19 which has a diameter slightly larger than that of the balls 16 and preferably a length sufficient to accommodate two of these balls. The operation of filling the balls 16 one at a time through the tube 19 into the bag 7 is controlled by a rocker 22 which is provided at both ends with cushions 20 and 21. As soon as a bag 7 arrives underneath tube 19 rocker 22 releases the ball which until this time has been held by the cushion 21 and permits it to drop into bag 7. At the same time by means of the cushion 20, rocker 22 prevents the superimposed ball from sliding downwardly. At the next pivoting movement of rocker 22 cushion 20 disengages from and releases the next ball 16, while cushion 21 blocks the outlet opening 23 of tube 19 until the next bag 7 arrives underneath tube 19. This releasing movement of cushion 20 also perimts a further ball to drop from the hopper 17 into tube 19.

The above procedure which has been described with reference to the first filling station also applies to all of the subsequent filling stations. After a bag 7 has passed the last filling station, the open upper end of the bag passes within the range of a carriage 25 which runs along a rail 24 and is provided with gripping means 26 which then grip this bag 7, take it off the chains 13 and 15 and carry it toward a welding apparatus where at first a welding seam 29 is applied on bag 7 near its open end by an opposite pair of welding rods 28. After this first welding seam 29 has been formed by the welding rods 28 and the bag has thus been sealed hermetically these rods 28 are only slightly loosened from the bag to permit it then to be drawn upwardly between the welding rods 28 until the latter engage with the upper balls in bag 7. Instead of drawing the bag upwardly between welding rods 28, it is also possible to draw the welding rods downwardly along the bag until they engage with the upper balls therein. This wiping motion of welding rods 28 along bag 7 'or vice versa is preferably carried out until balls 16 are pushed tightly against each other and no gap remains in the bag within which the balls can move relative to each other. As the result of this wiping motion the air which is contained in the bag will be compressed and the walls of the bag will be reinforced by the interior air pressure. The bag then forms a tightly filled air cushion. Thereafter, the second welding seam 30 is applied by the welding rods 28; The hermetic closure of this welding seam 30 insures that the filled bag will retain its shape until opened;

FIGURE 6 illustrates a modification of the welding operation. After being filled, the plastic bag is passed between two rollers 32 and 33, each of which is provided on its peripheral surface with a pair of welding ridges 34a, 35a and 34b, 35b, respectively, which extend parallel to the axis of the respective roller and radially of each roller at an angle of, for example, 45 relative to each other. After the two associated welding ridges 34a and 34b have been applied upon the bag to form the first welding seam 29, the two rollers 32 and 33 are rotated in opposite directions and thereby compress the air in bag 7 until the other two associated welding ridges 35a and 35b act upon the bag and apply the second welding seam 30 thereon. The fiat strip 31 of the bag between the two welding seams 29 and 30' from which all air has been squeezed out may be used for printing advertising matter thereon.

Of course, the two welding seams may also be produced by ridgeless rollers 32 and 33 or a wide striplike seam may be formed on the bag while the rollers are rotated in opposite directions to compress the air in the bag.

Finally, the completely sealed bag 7 is ejected by suitable ejecting means and deposited in a storage container 36.

As already indicated, the method according to the invention is carried out fully automatically and all operations and movements beginning with the welding and cutting of the bags at the stations 5 and 6, as shown in FIG- URE 2, and up to the ejection of the completed bags which are ready for sale are preferably carried out by means of a central cam control and pistons which are movable in hydraulic or pneumatic cylinders.

Although my invention has been illustrated and described with reference to the preferred embodiments thereof, I wish to have it understood that it is in no way limited to the details of such embodiments, but is capable: of numerous modifications within the scope of the appended claims.

Having thus fully disclosed my invention, what I claim 1. A method of producing a package containing relatively delicate objects, comprising the steps of forming a plastic bag hermetically closed on three sides and having a fourth open filling side, attaching the bag by suction means to conveying chain means, moving the thus attached bag by the chain means past a plurality of filling stations where the delicate objects are dropped successively intQ the bag and air also admitted into the bag, then sealing said bag by tightly pressing the two layers of the unfilled part of said bag progressively upon each other from a line spaced from the filled part of said bag and adjacent to the open end of said filling side in a direction vertical to said line up to a second line closely adjacent to said filled part and substantially parallel to said first line and thereby compressing the air in said bag, and welding said bag at least along said second line so as to seal said objects and said compressed air hermetically in said bag.

2. A method of producing a package containing relatively delicate objects, comprising the steps of forming a plastic bag hermetically closed on three sides and having a fourth open filling side, filling said bag partly with said objects through said filling side and thereby also admitting air into said bag, inserting and clamping the filling side of the bag between a pair of welding rollers, then rotating the rollers in opposite directions so as to draw the unfilled part of the bag between said rollers from a line near the open end of said filling side in the direction vertical to said line toward the filled part of said bag and thereby compress the air contained in said filled part and welding a strip on the unfilled part of a width in accordance with the desired rate of compression of the air in said bag by means of the rollers simultaneously with the rotation of the rollers, so that the completely sealed bag forms an air cushion for protecting said objects from being damaged.

3. A method of producing a package containing relatively delicate objects comprising the steps of forming a plastic bag hermetically closed on three sides and having a fourth open filling side, filling said bag partly with said objects through said filling side and thereby also admitting air into said bag, inserting the filling side of the bag between a pair of welding elements, forming a first welding seam along a first line substantially parallel to the open end of the filling side by said welding elements, then drawing the unfilled part of the bag through the welding elements until such elements are located at a second line substantially parallel to the first line and closely adjacent the filled parts and while said elements are pressed tightly upon the two layers of the bag thereby compressing the air contained in said filled part, and then forming a second welding seam on said bag at said second line by means of the welding elements, so that the completely sealed bag forms an air cushion for protecting said objects from being damaged.

4. A method of successively producing packages containing relatively delicate objects, comprising the steps of extending a transparent sheet of plastic and shaping the same into a succession of separate bags, each having only one open side, then suspending each bag so that its open side faces upwardly, conveying said bags successively to a plurality of filling stations, dropping at each of said stations at least one object through said open side into each bag until said bag is partly filled and thereby also admitting air into each bag, and then sealing each bag by tightly pressing the two layers of the unfilled part of said bag progressively upon each other from a line spaced from the filled part of the bag and adjacent to said open side in a direction vertical to said line up to a second line closely adjacent to said filled part and sub stantially parallel to said first line and thereby compressing the air in the filled part of said bag, and welding each bag at least along said second line so as to seal said objects and said compressed air hermetically in said bag.

5. A method of producing-a package containing relatively delicate objects, comprising the steps of forming a plastic bag hermetically sealed on three sides and having a fourth open filling side, filling said bag partly with said objects through the filling side and also admitting air into the bag, inserting and clamping the filling side of the bag between a pair of equal welding rollers, each having a pair of longitudinal projections on the peripheral side of the roller extending substantially parallel to its axis and peripherally spaced from each other, forming a first welding seam on the unfilled part of the bag at a first line near the open end of the filling side by means of two associated project-ions on the two rollers, then rotating the rollers in opposite directions in pressing engagement with the bag to compress the air in the filled part of the bag until the other two associated projections on the two rollers engage with the bag at a second line toward the filled part of the bag, welding a second seam on the bag adjacent said filled part by means of said second associated projections and forming a welded strip on the unfilled part of the Width in accordance with the desired rate of compression of the air in the bag so that the completely sealed bag forms an air cushion for protecting the objects from being damaged.

References Cited by the Examiner UNITED STATES PATENTS 636,317 11/1899 Buhler 53--29 2,422,725 6/ 1947 Gillfillam. 2,423,890 7/ 1947 Hurt 5348 2,469,975 5/ 1949 McCloy 5 329 2,635,742 4/ 1953 Swartz et a1. 206-46 2, 83 5,5 96 5/ 1958 Kaufman. 2,976,660 3/ 1961 Piazze 53266 2,983,087 5/1961 Schofield 206-46 3,030,752 4/ 1962 Woskin 53--266 FOREIGN PATENTS 555,546 4/1958 Canada.

FRANK E. BAILEY, Primary Examiner. EARLE DRUMMOND, Examiner. 

1. A METHOD OF PRODUCING A PACKAGE CONTAINING RELATIVELY DELICATE OBJECTS, COMPRISING THE STEPS OF FORMING A PLASTIC BAG HERMETICALLY CLOSED ON THREE SIDES AND HAVING A FOURTH OPEN FILLING SIDE, ATTACHING THE BAG BY SUCTION MEANS TO CONVEYING CHAIN MEANS, MOVING THE THUS ATTACHED BAG BY THE CHAIN MEANS PAST A PLURALITY OF FILLING STATIONS WHERE THE DELICATE OBJECTS ARE DROPPED SUCCESSIVELY INTO THE BAG AND AIR ALSO ADMITTED INTO THE BAG, THEN SEALING SAID BAG BY TIGHTLY PRESSING THE TWO LAYERS OF THE UNFILLED PART OF SAID BAG PROGRESSIVELY UPON EACH OTHER FROM A LINE SPACED FROM THE FILLED PART OF SAID BAG AND ADJACENT TO THE OPEN END OF SAID FILLING SIDE IN A DIRECTION VERTICAL TO SAID LINE UP TO A SECOND LINE CLOSELY ADJACENT TO SAID FILLED PART AND SUBSTANTIALLY PARALLEL TO SAID FIRST LINE AND THEREBY COMPRESSING THE AIR IN SAID BAG, AND WELDING SAID BAG AT LEAST ALONG SAID SECOND LINE SO AS TO SEAL SAID OBJECTS AND SAID COMPRESSED AIR HERMETICALLY IN SAID BAG. 